Fix issues when running multiple jobs concurrently

While testing the automatic alias updates and old index deletion for #191, and @dr0i testing #149 at the same time, we've had some issues that we didn't encounter before. This pull requests fixes these:

- Hadoop jobs: Create unique map file names to fix issue with concurrent jobs (https://github.com/fsteeg/lodmill/commit/60c9184fa4850343f685c9a51cabfea8896347b9)
- Elasticsearch indexing: Move retry logic up to catch all NoNodeAvailableExceptions (https://github.com/fsteeg/lodmill/commit/82ce04e09451b93957a219b4b323c7d756679824)

Tested on staging, see indexes timestamped with `20140128-170216` at: http://quaoar2.hbz-nrw.de:9200/_plugin/head/